Abnormal auditory event-related potentials in Williams syndrome.

Individuals with Williams Syndrome (WS) have specific auditory characteristics, including hypoacusis and hyperacusis, and music appreciation skills. Little is known about the functionality of the central auditory nervous system (CANS) for sound processing in WS. Thus, the objective of the present study was to evaluate the functionality of the CANS in individuals with WS, based on auditory event-related potentials, as far as cognitive and behavioral aspects are concerned. The study was carried out with 17 individuals, seven females and ten males, between seven and 17 years old, with WS, and 17 individuals with typical development matched by sex and chronological age to individuals with WS. None of these individuals had middle ear impairment or hearing loss. The subjects were evaluated for intelligence quotient, loudness discomfort level, and auditory event-related potentials with Tone Burst stimuli, on the oddball paradigm; the parents also answered the MTA-SNAP-IV questionnaire. Hyperacusis was found in six WS individuals and two individuals with typical development. In the present study, WS individuals present longer latency and reduced amplitude for P1, N1, N2 and P3 components. These results, suggesting a delay and hypoactive responses of the CANS in this syndrome, that cannot be related to the cognitive or behavioral aspects of these individuals, but it indicates a cortical immaturity to process acoustic stimuli.